When she began her freshman year in 2011, Sydney embarked on a tumultuous transformation. She had been accepted to her “reach school," Duke University, where students seemed to strive for perfection both academically and socially.

The change came fast and without warning for Sydney, who asked to be referred to by her first name for this story to protect her privacy. In the classroom, she did not coast by as she had in high school. Her grades lagged, friendships both formed and...